The present invention relates to an outer sheathed endoscope in which an outer sheath for preventing an insertion portion from directly contacting with the body wall of a patient is detachably disposed.
In an outer sheathed endoscope, generally, an outer sheath for shielding a flexible insertion portion of the endoscope from the outside is formed so as to detachably cover the flexible insertion portion. When the outer sheath is replaced with a new one for each use, it is possible to completely eliminate infection among patients through the endoscope.
Such an outer sheathed endoscope is configured so that a flexible insertion portion whose outer diameter is substantially constant is simply coupled to an operation portion, thereby enabling the flexible insertion portion to be completely covered with an outer sheath to the extent of reaching a coupling end with the operation portion.
In the configuration in which a flexible insertion portion is simply coupled to an operation portion as described above, however, when the flexible insertion portion is sharply bent in the vicinity of a coupling portion with the operation portion, the flexible insertion portion sometimes buckles or breaks in a relatively easy manner in both a used state where an outer sheath is attached, and a stored state where an outer sheath is not attached.